Problems

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Total results29,461 problems

Chonggang Chonggang
Medium4
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Prime Game
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Frozen Food
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Need for Speed
Medium4
Binary search, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Secret Chamber at Mount Rushmore
Medium4
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Wookje's Dinner Wheel
Medium4
Array, Hash map+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Juno hates birds!!
Medium4
Array, Implementation
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
A Taste of Queries
Medium4
Array, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Multiples of three from 0, 1, and 2 (Large)
Medium4
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Stephen Query
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
The TA is a sadist!!
Medium4
Dynamic programming, Binary search+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
STOP USING MONEY
Medium4
Sorting, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cut Vertices and Bridges
Medium4
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Is Yeongwoo a cheater?
Medium4
Simulation, Graph+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Favourite Times
Medium4
Math, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Milk Festival
Medium4
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Seven Warlords
Medium4
Sorting, Heap+2
No attempts yet
Time limit
10s
Memory limit
256 MB
Judgeable
Venue Rental (Small)
Medium4
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
MultiMax
Medium4
Sorting, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pizza Boxes
Medium4
Array, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Telescope
Medium4
Sliding window, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Party Games
Medium4
String, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Eenie Meenie Miney Moe
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ax+Bsin(x)=C II
Medium4
Binary search, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bathroom Stalls (Small1)
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Steed 2: Cruise Control (Small)
Medium4
Math, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Ample Syrup (Small)
Medium4
Brute force, Sorting+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Jaehong's Ladder
Medium4
Math, Geometry+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Gears
Medium4
Implementation, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sum of all pairwise products
Medium4
Math, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
FA
Medium4
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sogang Ground
Medium4
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Untangling Chain
Medium4
Simulation, Implementation
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Taro's Shopping
Medium4
Two pointers, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Almost Identical Programs
Medium4
String, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Forest Picture
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dark Ride with Monsters
Medium4
Array, Graph+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Go Northwest!
Medium4
Hash map, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Frog Leaps
Medium4
Greedy, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Irrational Division
Medium4
Game theory, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jogo de Boca
Medium4
Game theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Complete Naebbirac's sequence
Medium4
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Prime Driving Conditions
Medium4
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Anti-missile intercept
Medium4
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Treating Fractions Irrationally
Medium4
Math, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sheba's Amoebas
Medium4
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Workout for a Dumbbell
Medium4
Simulation, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Halfway Point
Medium4
Binary search, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Forbidden Zero
Medium4
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Filling an Arithmetic Sequence
Medium4
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Auxiliary Project
Medium4
Greedy, Math
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Clever Title
Medium4
Backtracking, Brute force+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Anticlockwise Motion
Medium4
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Byte Me!
Medium4
Bit manipulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Police Station
Medium4
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Wet Rock Peg Plan
Medium4
Simulation, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Olympiad Pizza
Medium4
Queue, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Counting paths
Medium4
Dynamic programming, Matrix
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Heart Rate
Medium4
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Frosh Week
Medium4
Greedy, Two pointers+2
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
ZigZag
Medium4
Sorting, Hash map+2
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Secret of Chocolate Poles
Medium4
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Programming Exam
Medium4
Prefix sum, Hash map+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Street Lights
Medium4
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Automobile
Medium4
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Go Go Go Special Action Force!
Medium4
Implementation, Matrix+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
How to Eat at a Buffet
Medium4
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Frosting on the Cake
Medium4
Array, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
GlitchBot
Medium4
Simulation, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wizard of Odds
Medium4
Math, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Treasure Hunt
Medium4
Simulation, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Bovine Shuffle
Medium4
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Milk Measurement
Medium4
Simulation, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Coloring Intervals
Medium4
Sorting, Intervals+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Maximum of A[j]-A[i]+A[l]-A[k]
Medium4
Dynamic programming, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Strange Tower of Hanoi
Medium4
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
League of Overwatch at Moloco (Hard)
Medium4
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Window
Medium4
Array, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
RPG Maker
Medium4
Implementation, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Best Matched Pair
Medium4
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Timovi
Medium4
Math, Simulation+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Out of Place
Medium4
Sorting, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Divisor Pairs
Medium4
Math, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Glen
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
N and M (7)
Medium4
Backtracking, Recursion+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N and M (8)
Medium4
Backtracking, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N and M (9)
Medium4
Backtracking, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N and M (11)
Medium4
Backtracking, Recursion+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
N and M (12)
Medium4
Backtracking, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Othello
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Search in a Grid
Medium4
Array, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Fantasy Pair
Medium4
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
N-Step Syllogism
Medium4
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Jujisu
Medium4
Prefix sum, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Counting equilateral triangles
Medium4
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Big Integer A+B
Medium4
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hoofball
Medium4
Sorting, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Taming the Herd
Medium4
Greedy, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lemonade Line
Medium4
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Segmentation
Medium4
Hash map, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Chonggang ChonggangRun a single-source shortest path from Jinseo's house, find the nearest type A and type B house, and report the closer type (A wins ties).	Medium4	Shortest pathGraph+2	No attempts yet	1s	256 MB	Judgeable
Prime GameSimulate a two-player game where each spoken prime is recorded per player, duplicates cost 1000 points, and a non-prime gives the opponent their third largest prime or 1000.	Medium4	SimulationImplementation+2	No attempts yet	2s	256 MB	Judgeable
Frozen FoodCount the minutes from a start time to an end time, inclusive, whose HH:MM display contains the digit N at least once.	Medium4	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Need for SpeedGiven segment distances and speedometer readings plus a total time, find the constant offset c making the summed travel times equal t.	Medium4	Binary searchMath+1	No attempts yet	1s	512 MB	Judgeable
Secret Chamber at Mount RushmoreGiven directed letter translations, decide for each pair of words whether every letter of the first can reach the matching letter of the second.	Medium4	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
Wookje's Dinner WheelGiven a sequence where each menu number appears exactly twice, find the maximum number of values seen once but not yet seen twice at any point.	Medium4	ArrayHash map+2	No attempts yet	2s	256 MB	Judgeable
Juno hates birds!!Given an n by m grid of numbers, remove the row or column containing the most digit 9s (ties broken by scanning order) and count the remaining 9s.	Medium4	ArrayImplementation	No attempts yet	2s	256 MB	Judgeable
A Taste of QueriesGiven a sequence of n numbers, process q queries that either report a range sum and then swap two positions, or report one range sum minus another.	Medium4	ArrayPrefix sum+2	No attempts yet	2s	256 MB	Judgeable
Multiples of three from 0, 1, and 2 (Large)Count N-digit numbers made only of the digits 0, 1, and 2 that are divisible by 3, with no leading zero, modulo 1e9+9.	Medium4	Dynamic programmingCombinatorics+1	No attempts yet	2s	256 MB	Judgeable
Stephen QuerySimulate N rounds of survival rock paper scissors and report the longest number of consecutive wins by any single player.	Medium4	SimulationImplementation+1	No attempts yet	2s	256 MB	Judgeable
The TA is a sadist!!Given a permutation of 1 to N, find the minimum number of elements to remove so the remaining values increase from front to back.	Medium4	Dynamic programmingBinary search+2	No attempts yet	2s	256 MB	Judgeable
STOP USING MONEYSort N games by satisfaction-to-price ratio, then by lower price, then by game number, and print the first K game numbers.	Medium4	SortingMath+2	No attempts yet	1s	512 MB	Judgeable
Cut Vertices and BridgesGiven a tree with N vertices and queries, report for each query whether a specified vertex is a cut vertex or a specified edge is a bridge.	Medium4	TreeDFS+2	No attempts yet	1s	512 MB	Judgeable
Is Yeongwoo a cheater?Given building dependencies and a log of build and destroy events, decide whether every event is legal without the cheat key.	Medium4	SimulationGraph+1	No attempts yet	1s	512 MB	Judgeable
Favourite TimesCount how many times in D minutes a 12-hour clock shows a time whose digits form an arithmetic sequence, starting at 12:00 inclusive.	Medium4	MathSimulation+2	No attempts yet	1s	512 MB	Judgeable
Milk FestivalGiven a sequence of shops selling milk types 0, 1, 2, find the longest subsequence whose values cycle 0,1,2,0,1,2,... in order.	Medium4	Dynamic programming	No attempts yet	1s	256 MB	Judgeable
The Seven WarlordsGiven up to ten million student grades, output the seven lowest grades in increasing order, one per line. Ties on the cut line still yield exactly seven grades.	Medium4	SortingHeap+2	No attempts yet	10s	256 MB	Judgeable
Venue Rental (Small)Given up to 100 axis-aligned rectangles, find the area of the union of all rectangles.	Medium4	ArrayImplementation+2	No attempts yet	2s	256 MB	Judgeable
MultiMaxGiven n cards with values in [-1000, 1000], pick two or three so their product is maximized.	Medium4	SortingGreedy+1	No attempts yet	1s	512 MB	Judgeable
Pizza BoxesGiven a grid of distinct pile heights, find how many boxes can be removed while keeping the per-row and per-column maxima unchanged.	Medium4	ArrayGreedy+2	No attempts yet	1s	512 MB	Judgeable
TelescopeCount the horizontal shifts of an m by l weight grid over an m by n path where the weighted sum exceeds W.	Medium4	Sliding windowPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
Party GamesFor each test case, find the shortest string that splits the sorted guest names into two equal halves, choosing the alphabetically first if several have that length.	Medium4	StringSorting+1	No attempts yet	2s	512 MB	Judgeable
Eenie Meenie Miney MoeSimulate elimination in a circle of N heifers using a repeating sequence of up to L step sizes, and report the last heifer left.	Medium4	SimulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Ax+Bsin(x)=C IIFind the unique positive x with Ax + B sin(x) = C, given 0 < B <= A, and print it to nine decimals.	Medium4	Binary searchMath	No attempts yet	2s	512 MB	Judgeable
Bathroom Stalls (Small1)Simulate K people choosing stalls by a fixed farthest-from-others rule and report the distances around the stall the last person takes.	Medium4	SimulationImplementation+2	No attempts yet	5s	512 MB	Judgeable
Steed 2: Cruise Control (Small)Given horses ahead on a one-way road that slow to match slower horses they catch, find the fastest constant speed Annie can hold to her destination without ever passing one.	Medium4	MathImplementation+2	No attempts yet	5s	512 MB	Judgeable
Ample Syrup (Small)Choose K pancakes from at most 10 to stack largest radius on the bottom, maximizing the exposed surface area divided by pi.	Medium4	Brute forceSorting+2	No attempts yet	5s	512 MB	Judgeable
Jaehong's LadderGiven a rectangle's width, height, and a number of vertical strips, sum the lengths of the N-1 rungs where the strips cross the rectangle's diagonals.	Medium4	MathGeometry+2	No attempts yet	2s	512 MB	Judgeable
GearsSimulate K gear turns; each turn makes a named gear rotate and may propagate to neighbors when the touching poles differ, then print a weighted score from the four top teeth.	Medium4	ImplementationSimulation+1	No attempts yet	2s	512 MB	Judgeable
Sum of all pairwise productsGiven n integers, compute the sum of x_a * x_b over all pairs with a < b.	Medium4	MathPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
FAStarting from a huge integer x, repeatedly replace it with (first digit) times (digit count) and report whether the sequence eventually cycles forever.	Medium4	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Sogang GroundGiven a weighted undirected graph, find a region whose total item count within distance m is largest.	Medium4	GraphShortest path+1	No attempts yet	1s	128 MB	Judgeable
Untangling ChainGiven edge turn directions, rebuild the chain by always extending the current bounding box by one in the heading direction and print the resulting edge lengths.	Medium4	SimulationImplementation	No attempts yet	0.5s	512 MB	Judgeable
Taro's ShoppingGiven item prices and a budget, find the largest sum of two distinct items that does not exceed the budget.	Medium4	Two pointersSorting+1	No attempts yet	2s	512 MB	Judgeable
Almost Identical ProgramsGiven two program strings, decide whether they are identical, differ only in one string literal at the same position, or are otherwise different.	Medium4	StringImplementation+1	No attempts yet	2s	512 MB	Judgeable
Forest PictureDraw an ASCII forest on an M by M canvas from tree or stump coordinates, clipping shapes that fall outside and framing the result with asterisks.	Medium4	ImplementationSimulation+2	No attempts yet	2s	512 MB	Judgeable
Dark Ride with MonstersGiven a permutation of misplaced monsters, find the minimum number of swaps needed to sort all monsters into their correct chambers.	Medium4	ArrayGraph+2	No attempts yet	5s	512 MB	Judgeable
Go Northwest!Given N distinct points, find the probability that two independently drawn points lie on a 45-degree diagonal from each other.	Medium4	Hash mapMath+1	No attempts yet	2s	512 MB	Judgeable
Frog LeapsFind the minimum sum of squared jump distances to travel from the first stop to the last, given sorted positions.	Medium4	GreedyDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Irrational DivisionTwo players alternately cut whole columns off the west and rows off the south of a p by q chessboard chocolate; compute the optimal final score difference.	Medium4	Game theoryDynamic programming	No attempts yet	2s	512 MB	Judgeable
Jogo de BocaGiven the target N, decide whether the first player can win the 1-2 counting game and which opening move (1 or 2) wins.	Medium4	Game theoryMath	No attempts yet	1s	1024 MB	Judgeable
Complete Naebbirac's sequenceGiven a multiset of values 1..K, find the single add, remove, or replace operation that makes every value appear equally often.	Medium4	ArrayHash map+1	No attempts yet	1s	1024 MB	Judgeable
Prime Driving ConditionsGiven a starting license plate, find the lexicographically first plate at or after it whose four digit number is prime.	Medium4	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Anti-missile interceptGiven the missile parabola and the anti-missile launch point and speed, decide the firing time and angle that intercepts at time tK, or report failure.	Medium4	GeometryMath+1	No attempts yet	2s	512 MB	Judgeable
Treating Fractions IrrationallyWrite the decimal of n/d cut off at the first 0 or 9, rounding down at 0 and up at 9, or throw it out if neither digit ever appears.	Medium4	MathSimulation+1	No attempts yet	2s	512 MB	Judgeable
Sheba's AmoebasCount the number of disjoint closed loops formed by black pixels on a grid, where each black pixel has exactly two black neighbors among its eight surrounding cells.	Medium4	GraphDFS	No attempts yet	2s	512 MB	Judgeable
Workout for a DumbbellSimulate Jim's three passes over 10 machines where each machine already has a repeating user, and Jim waits whenever the machine is busy.	Medium4	SimulationMath+1	No attempts yet	2s	512 MB	Judgeable
Halfway PointGiven n, find the value printed when the pair-comparison loop reaches its halfway point (the last item index printed there).	Medium4	Binary searchMath+2	No attempts yet	1s	512 MB	Judgeable
Forbidden ZeroGiven a positive integer n with no digit 0, find the next integer in increasing order that also contains no digit 0.	Medium4	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Filling an Arithmetic SequenceTwo terms of a ten-term arithmetic sequence are given at unknown positions; fill in the rest with integers or report that no integer completion exists.	Medium4	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Auxiliary ProjectChoose any multiset of digits whose total lit segments equals n, and maximize the sum of the digits.	Medium4	GreedyMath	No attempts yet	3s	512 MB	Judgeable
Clever TitleFor each uppercase word, count how many orderings of the n author names let you pick one uppercase letter from each name, left to right, to spell the word.	Medium4	BacktrackingBrute force+2	No attempts yet	5s	512 MB	Judgeable
Anticlockwise MotionGiven two cells of an anticlockwise spiral numbered from the center, find the Manhattan distance between them.	Medium4	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Byte Me!Given N data bytes and a parity byte, find the parity type, the one data byte with wrong popcount parity, and the flipped bit position.	Medium4	Bit manipulationImplementation+1	No attempts yet	2s	512 MB	Judgeable
Police StationIn a directed graph, list every vertex from which all other vertices are reachable by following arrows forward.	Medium4	GraphDFS+1	No attempts yet	2s	1024 MB	Judgeable
Wet Rock Peg PlanSimulate a sequence of peg placements and removals on a dependency DAG, tracking peak peg count and the first wet-rule violation.	Medium4	SimulationGraph+2	No attempts yet	2s	512 MB	Judgeable
Olympiad PizzaContestants queue for pizza slices; each takes one slice per turn and rejoins the back if still hungry. Report the second each finishes.	Medium4	QueueSimulation+2	No attempts yet	2s	512 MB	Judgeable
Counting pathsCount paths from the top-left to the bottom-right of a grid, moving only right or down and avoiding obstacle cells, modulo 10^9 + 7.	Medium4	Dynamic programmingMatrix	No attempts yet	2s	512 MB	Judgeable
Heart RateGiven a beat count b over p seconds, find the lower and upper bounds on the constant-interval heart rate that could produce it, plus the estimate 60b/p.	Medium4	MathImplementation+2	No attempts yet	2s	512 MB	Judgeable
Frosh WeekGiven task durations and quiet-interval lengths, each between 100000 and 199999, pair tasks with intervals that fit them and maximize the number of completed tasks.	Medium4	GreedyTwo pointers+2	No attempts yet	4s	512 MB	Judgeable
ZigZagGiven K words and N letters, output for each letter the word starting with it that has been used fewest times, breaking ties alphabetically.	Medium4	SortingHash map+2	No attempts yet	2s	64 MB	Judgeable
Secret of Chocolate PolesCount sequences of dark and white chocolate disks, each 1 cm thick except dark thick disks at k cm, alternating colors, starting and ending dark, with total thickness at most l.	Medium4	Dynamic programmingCombinatorics	No attempts yet	1s	512 MB	Judgeable
Programming ExamFor each query, decide whether two given substrings of S are anagrams, printing DA or NE.	Medium4	Prefix sumHash map+1	No attempts yet	3s	128 MB	Judgeable
Street LightsGiven existing street lights that each cover K metres to both sides, find the minimum number of extra lights needed to light every metre from 1 to N.	Medium4	GreedySorting+2	No attempts yet	1s	64 MB	Judgeable
AutomobileStarting from a matrix where each cell holds its row-major index, apply K row and column multiplications and report the total sum modulo 1e9+7.	Medium4	MathImplementation+2	No attempts yet	1s	64 MB	Judgeable
Go Go Go Special Action Force!Given a 9x9 grid of position codes, check whether each of the three groupings (columns, rows, and 3x3 blocks) contains all nine distinct codes.	Medium4	ImplementationMatrix+2	No attempts yet	3s	512 MB	Judgeable
How to Eat at a BuffetGiven a plate area and items with value per area and available area, pick fractions to maximize total value on the plate.	Medium4	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Frosting on the CakeGiven vertical stripe widths A and horizontal stripe heights B, find the total area of each of the three colors where each cell's color is (i+j) mod 3.	Medium4	ArrayMath+2	No attempts yet	5s	512 MB	Judgeable
GlitchBotFind which single instruction in a list of Left, Right, and Forward must be changed, and to what, so the robot ends at the given target.	Medium4	SimulationBrute force+1	No attempts yet	2s	512 MB	Judgeable
Wizard of OddsGiven N possible secret numbers and K yes/no questions, decide whether K adaptive questions always identify the number, where K questions distinguish at most 2^K outcomes.	Medium4	MathBinary search+2	No attempts yet	2s	512 MB	Judgeable
Treasure HuntFollow a grid of arrows from the top-left cell and report the number of steps to the treasure, Out if you leave the grid, or Lost if you loop forever.	Medium4	SimulationGraph+2	No attempts yet	2s	512 MB	Judgeable
The Bovine ShuffleGiven a permutation describing one shuffle and the cow order after three shuffles, recover the original order before the shuffles.	Medium4	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
Milk MeasurementThree cows start at 7 gallons; apply N dated changes in chronological order and count the days on which the set of cows holding the top output changes.	Medium4	SimulationSorting+2	No attempts yet	2s	512 MB	Judgeable
Coloring IntervalsGiven n closed intervals with distinct endpoints, find the minimum number of colors so that overlapping intervals get different colors.	Medium4	SortingIntervals+2	No attempts yet	3s	512 MB	Judgeable
Maximum of A[j]-A[i]+A[l]-A[k]Given an array, choose four increasing indices i<j<k<l maximizing A[j]-A[i]+A[l]-A[k].	Medium4	Dynamic programmingArray+1	No attempts yet	2s	512 MB	Judgeable
A Strange Tower of HanoiSimulate a fixed rule-based procedure that rearranges disks of arbitrary radii on three rods and outputs the resulting move sequence.	Medium4	SimulationImplementation	No attempts yet	2s	512 MB	Judgeable
League of Overwatch at Moloco (Hard)Given n employees and m conflict pairs, decide whether the employees can be split into two non-empty groups so that no pair shares a group.	Medium4	GraphDFS+1	No attempts yet	2s	512 MB	Judgeable
WindowGiven N panes of size W by H, slide odd-indexed panes east and even-indexed panes west by given distances, then compute the uncovered window area.	Medium4	ArraySimulation+2	No attempts yet	2s	512 MB	Judgeable
RPG MakerGiven a sparse grid of cities on odd coordinates, build a fixed Hamiltonian cycle ordering and cut it at the last city, marking the resulting path as roads.	Medium4	ImplementationSimulation+1	No attempts yet	2s	512 MB	Judgeable
Best Matched PairGiven up to 1000 distinct integers, find the largest product of two whose product's decimal digits form a consecutive increasing run like 123; print -1 if none exists.	Medium4	ImplementationBrute force+2	No attempts yet	2s	512 MB	Judgeable
TimoviKids are dealt into N teams in a bouncing 1..N..1 order, K per visit, until fewer than K remain; report each team's final count.	Medium4	MathSimulation+2	No attempts yet	1s	64 MB	Judgeable
Out of PlaceGiven a row that came from a sorted row with one cow moved, find the minimum number of arbitrary swaps to sort it.	Medium4	SortingGreedy+1	No attempts yet	2s	512 MB	Judgeable
Divisor PairsGiven n integers, count ordered pairs (i, j) with i != j such that a_i divides a_j.	Medium4	MathArray+2	No attempts yet	2s	512 MB	Judgeable
GlenGiven a target pattern of marks on an N by M grid, produce the fixed boustrophedon walk that flips tiles down-and-back to match the pattern.	Medium4	SimulationImplementation+2	No attempts yet	1s	256 MB	Judgeable
N and M (7)Given N distinct numbers and a length M, print every length-M sequence drawn from the numbers with repetition allowed, deduplicated and in increasing lexicographic order.	Medium4	BacktrackingRecursion+2	No attempts yet	1s	512 MB	Judgeable
N and M (8)Given N distinct natural numbers and a length M, print all non-decreasing sequences of length M drawn from the numbers, in lexicographic order.	Medium4	BacktrackingSorting+1	No attempts yet	1s	512 MB	Judgeable
N and M (9)Given N numbers (with duplicates) and length M, print every distinct length-M selection in increasing lexicographic order, using each copy at most once.	Medium4	BacktrackingSorting+1	No attempts yet	1s	512 MB	Judgeable
N and M (11)Given N numbers and a length M, list every length-M sequence drawn from the numbers, allowing repeats, in increasing lexicographic order without duplicates.	Medium4	BacktrackingRecursion+2	No attempts yet	1s	512 MB	Judgeable
N and M (12)Given N numbers and a length M, list all non-decreasing length-M sequences drawn from the numbers with repetition, in lexicographic order.	Medium4	BacktrackingSorting+2	No attempts yet	2s	512 MB	Judgeable
OthelloGiven the sequence of moves of a valid 6x6 Othello game, replays them and prints the final board plus the winner.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Word Search in a GridDecide whether a word appears in a grid along a straight line of neighboring cells in any of the eight directions.	Medium4	ArraySimulation+2	No attempts yet	2s	512 MB	Judgeable
Fantasy PairFor each pair of string lengths A and B, decide whether their sum can be written as a sum of two primes.	Medium4	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
N-Step SyllogismEach premise says all a are b; for each conclusion x is y, decide whether following the implication chain from x reaches y.	Medium4	GraphDFS+2	No attempts yet	2s	128 MB	Judgeable
JujisuGiven an N by M grid of populations, answer K queries for the sum of people inside each requested rectangle.	Medium4	Prefix sumArray+2	No attempts yet	2s	512 MB	Judgeable
Counting equilateral trianglesGiven a triangular tower with N layers of unit triangles, count every equilateral triangle of any size, both upward and downward pointing.	Medium4	MathCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Big Integer A+BRead two integers up to 10^10000 in magnitude and print their sum without using built-in big integer support.	Medium4	ImplementationString+2	No attempts yet	1s	512 MB	Judgeable
HoofballSort cows by position, then find the minimum number of starting balls so every cow receives the ball at least once under the nearest-cow passing rule.	Medium4	SortingGraph+1	No attempts yet	2s	512 MB	Judgeable
Taming the HerdGiven a partial daily log of days-since-breakout values with a breakout on day 1, find the minimum and maximum possible breakouts.	Medium4	GreedyArray+2	No attempts yet	2s	512 MB	Judgeable
Lemonade LineGiven each cow's maximum tolerated queue length, choose an arrival order that minimizes how many cows end up waiting in line.	Medium4	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
SegmentationTrack visits per user over time and answer queries by mapping each user's recency and frequency to one of 12 RF segments.	Medium4	Hash mapImplementation+2	No attempts yet	1s	1024 MB	Judgeable